Air Purifier VS Humidifier VS Dehumidifier: What’s The Differences

The ULTIMATE battle between air purifier, humidifier, and dehumidifier! Even though they are completely different devices, many people think otherwise hence the existence of this post. We will briefly go through each device's functionality to clear any initial confusion. Then we will touch on the differences versus each other and why should you get THE one. If you have been shopping for either of these three cleaning purifiers, this is a good place to start.
Short answer
Air purifier cleans air. Humidifier adds moisture. Dehumidifier removes moisture.

What is a Humidifier and Dehumidifier?

Humidifier is a device that increases the humidity level in a room. Dehumidifier works the opposite by decreases humidity in a room. There are 4 common types of humidifiers in the market: Evaporative, Steam vaporizer/ Mist, Ultrasonic, and Impeller. As for dehumidifier, there are Refrigeration, Absorption/ Electronic desiccant, Thermoelectric, and Ionic membrane.

Air Purifier VS Humidifier VS Dehumidifier

Air Purifier



Small to Large Typically smallSmall to Large
Purify Air
Humidity Level
Not affected Increase Decrease
Variants (Types)
Quarterly to AnnuallyRegularlyRegularly
Noise Level
Soft to Loud Soft to NormalAverage to Loud
Cost including Upkeeping
Highest CheapestAverage

So Air Purifier, Humidifier or Dehumidifier?

Short and sweet: Air purifier plus humidifier or dehumidifier. The sweet spot for humidity in a room is between 30 to 50 percent. You need to figure out what is needed and what works best to maintain a longevity clean air.

Need a little bit more convincing? Better air quality means better health and quality of life. If you experience ANY allergic symptoms consistently, get an air cleaner. Humidifier if you have a dry throat, flaky skin, or sinus just after waking up. Home constantly infested with mold, dehumidifier it is. Summer air = high humidity, winter air = low humidity. Pro tip: There are seasonal allergies or even haze invasion. During that period, most purifiers would be sold off thus there is limited room for price bargaining. So please be well-prepared before it happens.

How About Air Purifier with Built-in Humidifier? Yay or Nay?

I have nothing against an air purifier humidifier combination if it can deliver the “goods” (airflow output). You will use less electricity and have one less device to maintain. It’s not the best choice if you have a budget constraint. Also, most top models in the states is a standalone unit rather than a combo. If you don’t mind eating up your interior space, there is no difference in having two units running at the same time. Both air purifier and humidifier will complement each other existence well.

Let's begin with some positive news from EPA. With more and more people living the American dream, the population is on a steady growth since 1970. Even better news, the six common emissions (PM2.5 and PM10, SO2, NOx, VOCs, CO, and Pb) are dropped by a whopping 74 percent in 2018. This is also reflected in the low 799 combined days reaching above Air Quality Index (AQI). Less than twice the year 2000 combined 2,076 unhealthy days. Is no rocket science that, when outdoor air is good, indoor air quality follows suit.

What is an Air Purifier and How It Works?

AKA air cleaner is a device that pulls in and traps airborne irritants in the air. This includes dust, dust mite, pet dander, mold, pollen, mildew, bacteria, and viruses. With an activated carbon filter, it can remove smoke from cigarette, miscellaneous odors, chemical fumes and so much more. With all harmful particles trapped, the air purifier can circulate back clean air to the room. There are many different types of air purifier in the market, we always recommend people to go with a conventional HEPA air purifier. It is the safest, the most efficient and proven on its reliability.

Max Fernandez

Max Fernandez is a loving father and a dedicated reviewer of air purifier for home. He is also one of the million patients currently suffering from asthma. Besides covering regular news and updates on air quality, he has also reviewed more than 1000 air purifiers under his belt.